Different types of scaffolding systems are known. US patent publication U.S. Pat. No. 4,044,523 discloses a scaffolding system, provided with standards and ledgers. The standards are provided at regular distances with annular flanges in which cut-outs are provided. The ledgers are provided at their extremities with couplings having a slot extending in horizontal direction, in which an annular flange of a standard can be received. The coupling is further provided with a wedge which can be inserted through a cut-out into the flange and, by striking the wedge into place a coupling between a ledger and a standard can be rapidly realized. A drawback of this known scaffolding system is the presence of the annular flanges on the standards. These annular flanges complicate storage of the standards. The fact is that when the standards are stacked onto each other, the annular flanges provided at regular distances will complicate the relative sliding movement of the pipes so that taking such a standard from such a stack of standards is laborious. Furthermore, the presence of a number of annular flanges on a standard leads to a considerable increase in weight of the standard. Standards are often 2-2.5 meters long and every 500 mm an annular flange is attached to the standards. Due to the increase of the weight of the standard, the total working length of the standard is limited because with greater length, the total weight is no longer manageable for the scaffolding builder. In practice, the system disclosed in this patent is indicated as ring system.
Also known from practice is the so-called cup system. Such a cup system is described in European patent application EP-0 409 051 A2. In particular FIG. 9 of this publication clearly shows the design of this cup system. On each standard, at regular distances, two cups are provided. The lower cup is fixedly connected to the standard and the top cup is movably connected to the standard. The ledgers are provided at the extremities with flanges that can be hooked into the cups. The top cup has an upper surface that inclines upward and the standard is provided with projections designed for cooperation with the upward inclining top surface. Through rotation of the top cup, the top cup can be clamped-in in downward direction between the ledger and the projection. Thus, a ledger can be rapidly and efficiently fixed. For the cup system, in principle, the same drawbacks hold true as for the above-described ring system.
GB 1,185,169 shows, in FIGS. 9-16, different variants of standards. These known standards are provided with welded-on brackets or with bolts mounted therein on which a ledger can be placed. For these brackets and bolts the same drawbacks hold true as mentioned hereinabove.
Yet another drawback, not yet mentioned, of the known systems is that the rings, cups, brackets or bolts are always provided on the standard at quite a large distance from each other. A customary distance may be 500 mm. This distance is a compromise between weight and flexibility. From a viewpoint of flexibility, it would be advantageous to provide the rings or cups at a smaller mutual distance, so that there is a greater freedom of choice with respect to the level at which the ledgers can be connected with the standards. However, from a point of view of weight reduction, a greater distance is of advantage. Apparently, 500 mm is an acceptable compromise. Advantages of the known systems are that several ledgers can be connected at the same level to a standard and that such a connection can be realized very rapidly by a scaffolding builder. Another advantage is that the ledgers are always connected to the standards at fixed positions so that a regular framework can be obtained in a simple manner.
The object of the invention is to obviate or alleviate the above-described drawbacks.